It's the perfect storm: Florida's steamy summer and last fall's electricity rate increases have combined to drive up residential and commercial utility costs.

Shocked residents, business owners and officials at public agencies opened bills the past several days to find payments up to twice the norm.

Bills in the $500 to $1,000 range more than doubled among Progress Energy Florida customers in the Tampa Bay area, from 1,984 in June 2005 to 4,348 last month.

Tampa Electric reported 451 more customers moving into the higher bracket, for a total of 4,729.

The jump in electricity costs has become the source of chatter from meeting rooms to living rooms, always producing a visceral response.

"It's ridiculous," St. Petersburg hair salon owner Eula Sherrod, 58, said as she washed an employee's hair. "Two hundred twenty one dollars. It ain't ever been this high."

With her head propped up on Sherrod's sink, just after the shampoo and wash, 33-year-old LoveVetta Gilliam of St. Petersburg opened her eyes and sighed.

"Mine was $330 ... I'm not even at home during the day," she said.

The rate increase itself isn't new. The Florida Public Service Commission approved it last November in response to higher costs of fuel utilities need to produce electricity. Florida power companies depend substantially on natural gas and oil to generate electricity.

The rates took effect Jan. 1.

But as summertime rolled in and air conditioners kicked on, electric bills skyrocketed.

Even energy conservation didn't prevent the higher bills.

"The overall usage that a consumer has may not have increased," said Todd Brown, a spokesman for the Florida Public Service Commission, which regulates utility companies. "But I'm sure that they are seeing a difference in their bills. Last year we had a pretty massive increase."

Progress residential customers rates rose to $109.56 for the first 1,000 kilowatt-hours of electricity per month, up $11.78. The rates are based on the estimated average use for the year.

For businesses, the utilities develop a rate scale related to such considerations as the size of the business and its electricity usage.

Rate increases for commercial operations in Progress Energy's service area ranged from 14 to 17 percent for small businesses to 18 to 22 percent for larger companies, said Cherie Jacobs, a spokeswoman for the utility.

For Tampa Electric business customers, the increase was 13 to 15 percent for companies that operated during a standard work week, according to Rick Morera, a company spokesman.

The residential and commercial rate increases alone drove up electric bills. Combined with the heat, they are raising the ire of consumers.

And the utilities are getting an earful.

Progress Energy says the rate hikes are partly responsible for the 2.3-million calls it received from customers during the first six months of this year - a 12 percent increase over last year.

Customers have raised a range of issues from requests for extensions on their bills to inquiries about why their costs have gone up so high, Jacobs said.

"This is the time of year when people are running their air conditioning more because it is hot and humid and they want relief from that," she said. "If you're using your power, your bills are going to go up."

Morera, the Tampa Electric spokesman, said customers should ask utilities for free home inspections to help conserve energy.

"Obviously, with folks having issues with their high bills, we want to offer them the services that can help," Morera said.

Still, for some, it's going to be difficult.

Charles Kaupp of Lutz, whose company tests and adjusts air conditioning systems, said he works with some residential customers whose homes are 6,000 square feet or more.

"They're experiencing more in the $500-$600 utility bills," Kaupp said. "But those are homes that ... are huge."

Hillsborough County's school system paid $5.7-million for electricity in May and June combined this year, compared to $4.7-million for the same two months last year. That's an increase of about 21 percent. But part of the reason is that the school system is operating six more schools this year than last, spokeswoman Kristin Waskiewicz said.

Individuals and businesses continue to seek new ways to curb their escalating utility costs.

In the suburban Bloomingdale community, Ted Grable, 55, a technology consultant who lives in a four-bedroom home, said he's keeping closer track of the kilowatts than dollars.

Grable, 55, has kept a spreadsheet with the past five years of kilowatt usage.

"I know that dollars are up, but my kilowatts are down," he said.

At St. Petersburg College, officials are taking a number of steps to save money. Thermostats in numerous buildings will be raised two degrees, to 76 degrees. The college also will install sensors in many of its academic spaces to ensure lights are off when a room is unoccupied.

"With these measures, we're hoping to save $350,000 for the entire year," said Susan Reiter, director of facilities planning and institutional service.

Even Publix Supermarkets is feeling the pinch. Responding to higher electric bills, the grocer has initiated a "Green Routine" campaign to remind employees to conserve energy. Workers are urged to turn off lights and unused computers and to close cooler doors, said Shannon Patten, a spokeswoman for the company.

"We, of course, are in the mode of saving electricity in any way we can," Patten said. She noted, however, that "there's no correlation between our electric prices and the prices of the groceries that we have in the store."

Some of those hit hardest by the rising electric costs - low-income residents and seniors on fixed incomes - had to turn to social agencies to help keep their lights on.

At Salvation Army locations in Pinellas and Hillsborough counties, the rate increases sent demand for assistance soaring.

The St. Petersburg branch of the Salvation Army recorded almost 700 requests for utility assistance in June, the first time the office began tracking such data. But social workers there were forced to turn away all but 82 customers because of a lack of funds. That branch offers grants of up to $150 once in a 12-month period.

"The need has outgrown the supply," said Rhonda Abbott, director of social services for the St. Petersburg branch. "Some of the folks are a paycheck away from being homeless."

Compared to last year, Tampa's Salvation Army said it has seen a doubling in the number of people who qualify for its SHARE program, which helps pay utility bills of people facing economic hardship.

Last June, 25 people asked for help, compared to 45 last month.

"Our auxiliary donated large box fans to us," said Jessica Hedgren, Salvation Army's family services director. "We have been distributing that to help lower their air conditioning bill."

Hedgren said she has seen steady growth of between five to 10 people a month.

Charlie Beck, deputy public counsel with the Office of Public Counsel, which represents the state's utility customers, said state officials are aware of the utility concerns and are reviewing the issue.

"It's frustrating to us, too," Beck said. "We're taking a good, close look. We do all we can but the biggest thing right now is the fuel prices are simply higher."